LG

/// <summary>
/// Variables pour le D&D.
/// </summary>
private Rectangle dragBoxFromMouseDown;
private int rowIndexFromMouseDown;
private int rowIndexOfItemUnderMouseToDrop;
 
#region IhmSynoptique D&D du DataGridView
/// <summary>
/// Drag & Drop : début de l'opération. Quand l'utilisateur enfonce le clic de la souris.
/// </summary>
/// <param name="sender">On s'en fout.</param>
/// <param name="e">Information de l'événement.</param>
private void dataGridView1_MouseMove(object sender, MouseEventArgs e)
{
  if (((e.Button & MouseButtons.Left) == MouseButtons.Left) && (dragBoxFromMouseDown != Rectangle.Empty && !dragBoxFromMouseDown.Contains(e.X, e.Y)))
  {
    // Proceed with the drag and drop, passing in the list item.
    dataGridView1.DoDragDrop(dataGridView1.Rows[rowIndexFromMouseDown], DragDropEffects.Move);
  }
}
 
/// <summary>
/// Drag & Drop : Un peu après le début de l'opération. Pour indiquer que le composant accepte le D&D en tant que destinataire.
/// </summary>
/// <param name="sender">On s'en fout.</param>
/// <param name="e">On s'en fout.</param>
private void dataGridView1_DragOver(object sender, DragEventArgs e)
{
  e.Effect = DragDropEffects.Move;
}
 
/// <summary>
/// Drag & Drop : vers la fin de l'opération. Quand l'utilisateur relâche le clic de la souris.
/// </summary>
/// <param name="sender">On s'en fout.</param>
/// <param name="e">Position de la souris.</param>
private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
{
  // Get the index of the item the mouse is below.
  rowIndexFromMouseDown = dataGridView1.HitTest(e.X, e.Y).RowIndex;
 
  if (rowIndexFromMouseDown != -1)
  {
    // Remember the point where the mouse down occurred.
    // The DragSize indicates the size that the mouse can move
    // before a drag event should be started.
    Size dragSize = SystemInformation.DragSize;
 
    // Create a rectangle using the DragSize, with the mouse position being
    // at the center of the rectangle.
    dragBoxFromMouseDown = new Rectangle(new Point(e.X - (dragSize.Width / 2), e.Y - (dragSize.Height / 2)), dragSize);
  }
  else
  {
    // Reset the rectangle if the mouse is not over an item in the ListBox.
    dragBoxFromMouseDown = Rectangle.Empty;
  }
}
 
/// <summary>
/// Drag & Drop : Fin de l'opération. Quand le logiciel applique réellement les modifications.
/// </summary>
/// <param name="sender">On s'en fout.</param>
/// <param name="e">Informations diverses du D&D.</param>
private void dataGridView1_DragDrop(object sender, DragEventArgs e)
{
  // The mouse locations are relative to the screen, so they must be
  // converted to client coordinates.
  Point clientPoint = dataGridView1.PointToClient(new Point(e.X, e.Y));
 
  // Get the row index of the item the mouse is below.
  // dataGridView1.HitTest peut valoir -1 si on lache sur l'entête de la colonne.
  rowIndexOfItemUnderMouseToDrop = dataGridView1.HitTest(clientPoint.X, clientPoint.Y).RowIndex;
 
  // If the drag operation was a move then remove and insert the row.
  if ((e.Effect == DragDropEffects.Move) && (rowIndexOfItemUnderMouseToDrop != -1))
  {
    DataGridViewRow rowToMove = e.Data.GetData(typeof(DataGridViewRow)) as DataGridViewRow;
    // nouvelle position : rowIndexOfItemUnderMouseToDrop.
    // ancienne position : rowIndexFromMouseDown.
    // Appliquer un traitement ici.
    dataGridView1.Rows.RemoveAt(rowIndexFromMouseDown);
    dataGridView1.Rows.Insert(rowIndexOfItemUnderMouseToDrop, rowToMove);
  }
}
#endregion

Select and drag a datagridview row with a single click Archive du 17/06/2009 le 28/04/2020

Ils ne marchent pas. Voir Touches.

Il faut passer par l'évènement DataGridView.CellFormatting.

Datagridview cell style update Archive du 09/11/2011 le 28/04/2020